import java.util.Iterator;
import java.util.LinkedList;

/*
 * @lc app=leetcode.cn id=706 lang=java
 *
 * [706] 设计哈希映射
 */

// @lc code=start
class MyHashMap {
    //沿着之前设计set的思路，hashmap其实就是把pair<int,int>放在一个set里了。
    // 这个有啥问题么，我没看出来
    private class Pair {
        private int key;
        private int value;

        public Pair(int key, int value) {
            this.key = key;
            this.value = value;
        }

        public int getKey() {
            return key;
        }

        public int getValue() {
            return value;
        }

        public void setValue(int value) {
            this.value = value;
        }
    }

    private static int NUM = 769;//质数，减少冲突。
    private LinkedList<Pair>[] data;

    /** Initialize your data structure here. */
    public MyHashMap() {
        data = new LinkedList[NUM];
        for(int i = 0 ;i<NUM ; i++){
            data[i] = new LinkedList<>();
        }
    }
    
    /** value will always be non-negative. */
    public void put(int key, int value) {
        int h = key%NUM;
        Iterator<Pair> it = data[h].iterator();
        while(it.hasNext()){
            Pair p = it.next();
            if( p.getKey() == key){
                p.setValue(value);//更改值
            }
        }
        data[h].offerLast(new Pair(key, value));//在末尾添加Key
    }
    
    /** Returns the value to which the specified key is mapped, or -1 if this map contains no mapping for the key */
    public int get(int key) {
        int h = key%NUM;
        Iterator<Pair> it = data[h].iterator();
        while(it.hasNext()){
            Pair p = it.next();
            if( p.getKey() == key){
                return p.getValue();
            }
        }
        return -1;
    }
    
    /** Removes the mapping of the specified value key if this map contains a mapping for the key */
    public void remove(int key) {
        int h = key%NUM;
        Iterator<Pair> it = data[h].iterator();
        while(it.hasNext()){
            Pair p = it.next();
            if( p.getKey() == key){
                data[h].remove(p);
            }
        }
    }
}

/**
 * Your MyHashMap object will be instantiated and called as such:
 * MyHashMap obj = new MyHashMap();
 * obj.put(key,value);
 * int param_2 = obj.get(key);
 * obj.remove(key);
 */
// @lc code=end

